Bio-Concrete Heals the Infrastructure Future

America’s infrastructure is failing, but what if “smart” materials such as concrete, metals, and plastics could heal themselves, creating a smarter infrastructure of the future?

This reality might not be too far off, as researchers and tech companies are working to provide this to the construction industry.

At its core, self-healing concrete addresses typical deficiencies in concrete that increases its maintenance costs and reduces its lifespan. It helps to fix problems such as permeability, micro-cracks, freeze/thaw damage, and waterproofness.

Lawrence Gasman, principal analyst, n-tech Research, says that self-healing materials in general are capable of healing small cracks and similar levels of damage.

“Although no one thinks that self-healing materials will ever be able to fix large holes, the point is that small cracks often turn into major damage over a period of time, so limited self-healing can be justified as more than just a cosmetic fix,” he explains.

With the ability to help “heal” infrastructure, these new materials could have an impact on the construction industry in the future.

Bio-Concrete: The Way Forward?

While various mechanisms are being attempted for self-healing concrete, bio-concrete is perhaps one of the most “famous,” according to Gasman.

Gasman explains that in bio-concrete, bacteria are the mechanism being used to do the healing. As far as he is aware, this type of material is still some way from commercialization.

Bio-concrete gained quite a bit of press last year when Henk Jonkers, a researcher at TU Delft and his bio-concrete of the future were nominated for a European Inventor Award—which is an initiative of the European Patent Office.

At its most simple form, the concrete is embedded with bacteria in it—and, according to Jonkers, is able to survive in concrete for more than 200 years.

If a crack forms, the concrete will heal itself. It is that simple.

The challenge, however, is bio-concrete will be expensive, explains Gasman of n-tech Research, but considering how much money is being spent on repairing roads, bridges, tunnels and sidewalks, there might be good cause for it.

He explains the first users will probably be large private buildings, such as headquarters of multinationals who want to promote a high-tech image. Still, he says it could be several decades before self-healing concrete is conventional. “Prices are going to have to come down a lot for this to happen,” he says.

And then, there are other forms of self-healing materials that are already available on the market today.

Chris Chen, director of Penetron Specialty Products, says bio-concrete is just one in a series of self-healing materials—and it is already having an impact on the construction industry.

“Crystalline self-healing products such as Penetron has been in use for decades, already providing self-healing protection for many commercial and industrial projects around the globe,” he explains. “By virtue of being implemented when the concrete is being placed, it allows savings in both time and labor for construction projects and extended lifespans for treated concrete.”

He adds that recent studies have proven that Penetron crystalline self-healing products can add as much as 60 additional years to a structure’s life.

Chen adds, “While (bio-concrete) shows promise, it has yet to prove itself in everyday commercial applications as crystalline self-healing systems have.” For contractors, Chen recommends taking a look at products that have a proven track record.

At the same time, Gasman says contractors that do become involved with these advanced materials should work very closely with the technologists who developed them. “Issues are almost certain to arise and working with the people who designed the material will certainly help to alleviate them.”

These “smart” materials could be part of the makeup of the next generation of smart cities and infrastructure.

Put Smarts in Structures

According to a report from n-tech Research released earlier this year, smart structures—which includes self-healing materials—in the construction industry will grow.

In fact, the research firm says the market for smart structures in buildings, bridges, and tunnels is about to take off based on improved energy efficiency, reduced construction costs, increasing the lifespan of buildings and even improving building aesthetics.

This fits in well with the latest trends toward IoT (Internet of Things), SHM (structural health monitoring) systems, and more.

The report also quantifies the opportunities for the smart materials and components used in the smart-building structures—which includes shape memory alloys and polymers, self-healing materials, a variety of sensors, and more.

In particular, the research firm looks to the future, and predicts smart structures will see the use of nitinol shape memory alloys to replace some traditional steel-and-concrete construction, using its ability to self-restore when a building or bridge comes under stress.

Overall, it predicts the total smart-building structure market will produce around $150 million in smart materials sales in 2021.

Another unique area that could see some traction is smart building skins, which are mostly found in high-profile projects and experimental buildings.

“Primarily, we see smart materials as being used for structural health-monitoring of large buildings, especially those that are vulnerable to seismic activity,” says Gasman of n-tech Research. “This can be based on conventional sensors. However, SHM will gradually be built into the fabric of the building itself using smart materials and the trend will be towards smart-building skins where the sensing functionality and usual functionalities of building envelopes have completely merged.”

The report also shows in the next few years, the focus will be on structural health-monitoring systems. Leveraging smart materials and sensors, structural health-monitoring will mature for seismic protection and turn it into a broader market.

Both materials and technologies used in construction continue to evolve—and will impact the industry in the next few years. As the need to improve energy efficiency, increase the lifespan of the building and lower the overall cost of construction continue to rise, so too will the use of technologies.

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